WASHINGTON — Six Texas congressmen are in the middle of a summertime political tempest sweeping the nation's capital over legislation to require future presidential candidates to show birth certificates to prove they are “natural born citizens” of the United States eligible to serve as president.

The effort by the lawmakers, including Houston-area Reps. Ted Poe, R-Humble, and John Culberson, R-Houston, stems from a so-called “birther movement” mounted by some conservative Republicans and talk-show hosts who continue to question whether President Barack Obama is a natural born citizen.

The Texans have not adopted the prove-it's-not-true approach pressed by talk-show hosts such as Rush Limbaugh, who insists “Barack Obama has yet to prove he's a citizen” and “all he'd have to do is show a birth certificate.” But the lawmakers' effort lends credence to what some dismiss as a fringe movement fanned by unsubstantiated rumors swirling on the Internet thanks to bloggers such as Californian Orly Taitz. “I believe it is a serious concern” that requires Congress to “subpoena all of Obama's vital records,” Taitz writes.

The Constitution stipulates that “no person except a natural born citizen” shall be eligible to serve as president. The Presidential Eligibility Act proposed in March by Rep. Bill Posey, R-Fla., would require campaign committees to submit a copy of the candidate's birth certificate to the Federal Election Commission with other documentation as necessary to prove eligibility.

Little League test

Poe, a former prosecutor and criminal court judge, says he “never said” Obama was born “anywhere but the United States,” but adds: “To ensure that we eliminate future debates and adhere to the Constitution, we simply should do what Little Leagues all across our country do and require that birth certificates be provided at the time of registration.”

Culberson says any candidate seeking federal elective office “should be required to prove that they meet the requirements laid out in our Constitution.”

Other former candidates have faced similar questions, including Republican presidential nominee John McCain, who was born in the Panama Canal Zone in 1936.

“Requiring future presidential candidates to provide their birth certificates in 2012 and thereafter is a commonsense way to avoid unnecessary controversies and conspiracy theories,” adds Rep. Louie Gohmert, R-Tyler.

Rep. Randy Neugebauer, R-Lubbock, collaborated on the bill in hopes of quelling stubborn controversies that are distractions and “not good for our nation,” said spokeswoman Michelle Ozanus.

Of the 10 co-sponsors enlisted by Posey, six are from Texas, including Poe, Culberson, Gohmert, Neugebauer, Kenny Marchant, R-Coppell and John Carter, R-Round Rock.

Rep. Sheila Jackson Lee, D-Houston, challenged what she described as a bid to impeach Obama's birthright as the first black president.

“In all my lifetime whether you are the winner or the loser, I have never heard of anyone raising the question of the birthplace of the duly elected president.”

State officials in Hawaii vouched for Obama's birth last month. They said state law prevents public release of an individual's birth certificate.